Re: [PATCH RESEND v9 02/13] iommu/ioasid: Add ioasid references
Hi Jean,
On 8/17/20 7:15 PM, Jean-Philippe Brucker wrote:
> Let IOASID users take references to existing ioasids with ioasid_get().
> ioasid_put() drops a reference and only frees the ioasid when its
> reference number is zero. It returns true if the ioasid was freed.
> For drivers that don't call ioasid_get(), ioasid_put() is the same as
> ioasid_free().
>
> Reviewed-by: Lu Baolu
> Signed-off-by: Jean-Philippe Brucker
Reviewed-by: Eric Auger
Thanks
Eric
> ---
> include/linux/ioasid.h | 10 --
> drivers/iommu/intel/iommu.c | 4 ++--
> drivers/iommu/intel/svm.c | 6 +++---
> drivers/iommu/ioasid.c | 38 +
> 4 files changed, 47 insertions(+), 11 deletions(-)
>
> diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
> index 6f000d7a0ddc..e9dacd4b9f6b 100644
> --- a/include/linux/ioasid.h
> +++ b/include/linux/ioasid.h
> @@ -34,7 +34,8 @@ struct ioasid_allocator_ops {
> #if IS_ENABLED(CONFIG_IOASID)
> ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
> void *private);
> -void ioasid_free(ioasid_t ioasid);
> +void ioasid_get(ioasid_t ioasid);
> +bool ioasid_put(ioasid_t ioasid);
> void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> bool (*getter)(void *));
> int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
> @@ -48,10 +49,15 @@ static inline ioasid_t ioasid_alloc(struct ioasid_set
> *set, ioasid_t min,
> return INVALID_IOASID;
> }
>
> -static inline void ioasid_free(ioasid_t ioasid)
> +static inline void ioasid_get(ioasid_t ioasid)
> {
> }
>
> +static inline bool ioasid_put(ioasid_t ioasid)
> +{
> + return false;
> +}
> +
> static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
> bool (*getter)(void *))
> {
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index e9864e52b0e9..152fc2dc17e0 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -5149,7 +5149,7 @@ static void auxiliary_unlink_device(struct dmar_domain
> *domain,
> domain->auxd_refcnt--;
>
> if (!domain->auxd_refcnt && domain->default_pasid > 0)
> - ioasid_free(domain->default_pasid);
> + ioasid_put(domain->default_pasid);
> }
>
> static int aux_domain_add_dev(struct dmar_domain *domain,
> @@ -5210,7 +5210,7 @@ static int aux_domain_add_dev(struct dmar_domain
> *domain,
> spin_unlock(>lock);
> spin_unlock_irqrestore(_domain_lock, flags);
> if (!domain->auxd_refcnt && domain->default_pasid > 0)
> - ioasid_free(domain->default_pasid);
> + ioasid_put(domain->default_pasid);
>
> return ret;
> }
> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> index 95c3164a2302..50897a2bd1da 100644
> --- a/drivers/iommu/intel/svm.c
> +++ b/drivers/iommu/intel/svm.c
> @@ -565,7 +565,7 @@ intel_svm_bind_mm(struct device *dev, int flags, struct
> svm_dev_ops *ops,
> if (mm) {
> ret = mmu_notifier_register(>notifier, mm);
> if (ret) {
> - ioasid_free(svm->pasid);
> + ioasid_put(svm->pasid);
> kfree(svm);
> kfree(sdev);
> goto out;
> @@ -583,7 +583,7 @@ intel_svm_bind_mm(struct device *dev, int flags, struct
> svm_dev_ops *ops,
> if (ret) {
> if (mm)
> mmu_notifier_unregister(>notifier, mm);
> - ioasid_free(svm->pasid);
> + ioasid_put(svm->pasid);
> kfree(svm);
> kfree(sdev);
> goto out;
> @@ -652,7 +652,7 @@ static int intel_svm_unbind_mm(struct device *dev, int
> pasid)
> kfree_rcu(sdev, rcu);
>
> if (list_empty(>devs)) {
> - ioasid_free(svm->pasid);
> + ioasid_put(svm->pasid);
> if (svm->mm)
> mmu_notifier_unregister(>notifier,
> svm->mm);
> list_del(>list);
> diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
> index 0f8dd377aada..50ee27bbd04e 100644
> --- a/drivers/iommu/ioasid.c
> +++ b/drivers/iommu/ioasid.c
> @@ -2,7 +2,7 @@
> /*
> * I/O Address Space ID allocator. There is one global IOASID space, split
> into
> * subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and
> - * free IOASIDs with ioasid_alloc and ioasid_free.
> + * free IOASIDs with ioasid_alloc and ioasid_put.
> */
> #include
> #include
> @@ -15,6 +15,7 @@ struct ioasid_data {
> struct ioasid_set *set;
> void *private;
> struct rcu_head rcu;
> + refcount_t refs;
> };
>
[PATCH RESEND v9 02/13] iommu/ioasid: Add ioasid references
Let IOASID users take references to existing ioasids with ioasid_get().
ioasid_put() drops a reference and only frees the ioasid when its
reference number is zero. It returns true if the ioasid was freed.
For drivers that don't call ioasid_get(), ioasid_put() is the same as
ioasid_free().
Reviewed-by: Lu Baolu
Signed-off-by: Jean-Philippe Brucker
---
include/linux/ioasid.h | 10 --
drivers/iommu/intel/iommu.c | 4 ++--
drivers/iommu/intel/svm.c | 6 +++---
drivers/iommu/ioasid.c | 38 +
4 files changed, 47 insertions(+), 11 deletions(-)
diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index 6f000d7a0ddc..e9dacd4b9f6b 100644
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h
@@ -34,7 +34,8 @@ struct ioasid_allocator_ops {
#if IS_ENABLED(CONFIG_IOASID)
ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
void *private);
-void ioasid_free(ioasid_t ioasid);
+void ioasid_get(ioasid_t ioasid);
+bool ioasid_put(ioasid_t ioasid);
void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
bool (*getter)(void *));
int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
@@ -48,10 +49,15 @@ static inline ioasid_t ioasid_alloc(struct ioasid_set *set,
ioasid_t min,
return INVALID_IOASID;
}
-static inline void ioasid_free(ioasid_t ioasid)
+static inline void ioasid_get(ioasid_t ioasid)
{
}
+static inline bool ioasid_put(ioasid_t ioasid)
+{
+ return false;
+}
+
static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
bool (*getter)(void *))
{
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index e9864e52b0e9..152fc2dc17e0 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5149,7 +5149,7 @@ static void auxiliary_unlink_device(struct dmar_domain
*domain,
domain->auxd_refcnt--;
if (!domain->auxd_refcnt && domain->default_pasid > 0)
- ioasid_free(domain->default_pasid);
+ ioasid_put(domain->default_pasid);
}
static int aux_domain_add_dev(struct dmar_domain *domain,
@@ -5210,7 +5210,7 @@ static int aux_domain_add_dev(struct dmar_domain *domain,
spin_unlock(>lock);
spin_unlock_irqrestore(_domain_lock, flags);
if (!domain->auxd_refcnt && domain->default_pasid > 0)
- ioasid_free(domain->default_pasid);
+ ioasid_put(domain->default_pasid);
return ret;
}
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 95c3164a2302..50897a2bd1da 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -565,7 +565,7 @@ intel_svm_bind_mm(struct device *dev, int flags, struct
svm_dev_ops *ops,
if (mm) {
ret = mmu_notifier_register(>notifier, mm);
if (ret) {
- ioasid_free(svm->pasid);
+ ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
@@ -583,7 +583,7 @@ intel_svm_bind_mm(struct device *dev, int flags, struct
svm_dev_ops *ops,
if (ret) {
if (mm)
mmu_notifier_unregister(>notifier, mm);
- ioasid_free(svm->pasid);
+ ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
@@ -652,7 +652,7 @@ static int intel_svm_unbind_mm(struct device *dev, int
pasid)
kfree_rcu(sdev, rcu);
if (list_empty(>devs)) {
- ioasid_free(svm->pasid);
+ ioasid_put(svm->pasid);
if (svm->mm)
mmu_notifier_unregister(>notifier,
svm->mm);
list_del(>list);
diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
index 0f8dd377aada..50ee27bbd04e 100644
--- a/drivers/iommu/ioasid.c
+++ b/drivers/iommu/ioasid.c
@@ -2,7 +2,7 @@
/*
* I/O Address Space ID allocator. There is one global IOASID space, split into
* subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and
- * free IOASIDs with ioasid_alloc and ioasid_free.
+ * free IOASIDs with ioasid_alloc and ioasid_put.
*/
#include
#include
@@ -15,6 +15,7 @@ struct ioasid_data {
struct ioasid_set *set;
void *private;
struct rcu_head rcu;
+ refcount_t refs;
};
/*
@@ -314,6 +315,7 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
ioasid_t max,
data->set = set;
data->private = private;
+ refcount_set(>refs, 1);
/*
* Custom allocator needs allocator data to perform
